Orders the variables of a polynomial OI-algebra according to $x_{i',j'} < x_{i,j}$ if $i'>i$ or $i'=i$ and $j'<j$.
The object RowDownColUp is a symbol.
The source of this document is in /build/reproducible-path/macaulay2-1.25.06+ds/M2/Macaulay2/packages/OIGroebnerBases.m2:1468:0.